A known example of such web takeup apparatus is disclosed in Japanese Utility Model Publication No. 51-276. This apparatus comprises an oscillatable guide member for guiding a web or film to a takeup core, and an arm member including a pressure roller at a distal end thereof for moving the guide member away in accordance with a radius of the film wound around the core. With this takeup apparatus, a film takeup operation is carried out after a leading end of the film is pressed upon the periphery of the takeup core and wound therearound twice or so.
Another known example is disclosed in Japanese Patent Publication No. 58-32149. This takeup apparatus comprises an oscillatable guide member for guiding a photographic material in the form of a rolled sheet to a takeup core, and a soft belt-like member attached to a distal end of the guide member for contacting the photographic material taken up by the core to press and tighten the material. With this takeup apparatus also, a takeup operation takes place after a leading end of the photographic material is wound around the periphery of the takeup core twice or so.
The foregoing known examples have various problems. In the first place, it is necessary in both examples to feed the web in an amount corresponding to twice the outer periphery of the takeup core prior to a takeup operation in order for the leading end of the web to wind around the takeup core. That amount of the web corresponding to twice the outer periphery of the core is therefore unavailable for recording images.
Second, it is difficult to always assure retention of the leading end of the web on the takeup core, which tends to result in detriments to a subsequent takeup operation. Third, the arm member or the belt-like member must be constructed and attached with great care, and complaints have been heard of its complexity also.
Other problems include possibilities of damage done to the web by the pressure applied to press the web against the takeup core. Such pressure must be strictly uniform transversely of the web, and any pressure imbalance may result in transverse deviations in the web winding and other serious consquences. The known apparatus have also been found unsatisfactory in that different widths of the web require different takeup apparatus specially suited thereto.